Diabet. Med. 28, 148–155 (2011)
Aims Insulin resistance and dyslipidaemia both increase cardiovascular risk in Type 1 diabetes. However, little data exist on the associations of insulin resistance to lipids in Type 1 diabetes. Our objective was to explore the associations between insulin resistance (assessed by glucose infusion rate) and lipids in people with Type 1 diabetes and determine whether adiposity and/or average glycaemia influence these associations.
Methods Hyperinsulinaemic–euglycaemic clamp studies were performed in 60 subjects with Type 1 diabetes aged 12–19 years (age 15 ± 2 years, 57% female, duration of diabetes 6.3 ± 3.8 years, HbA1c 8.6 ± 1.5%, IFCC = 70 mmol/mol) and 40 subjects with Type 1 diabetes aged 27–61 years (age 45 ± 9 years, 53% female, duration of diabetes 23 ± 8 years, HbA1c 7.5 ± 0.9%, IFCC = 58 mmol/mol). Multiple linear regression models were fit to examine the association between glucose infusion rate and fasting lipid levels with adjustment for possible confounders.
Results Lower glucose infusion rate was significantly associated with lower levels of HDL cholesterol in youths with Type 1 diabetes and with higher levels of triglycerides and higher triglyceride/HDL ratio in both youths and adults. The magnitude of the associations between glucose infusion rate and lipid levels translate into interquartile differences of 0.098 mmol/l for HDL cholesterol, 0.17 mmol/l for triglycerides and 1.06 for triglycerides/HDL in the adolescents and 0.20 mmol/l for triglycerides and 1.01 for triglycerides/HDL in the adults. The associations were attenuated and no longer statistically significant by adjustment for adiposity among adults, while adjustment for HbA1c had a small effect in youths and adults.
Conclusions Lower insulin sensitivity is associated with a more atherogenic lipid profile in both youths and adults with Type 1 diabetes.